filter data from an array of objects based on another array of objects

Question

I have any array of objects:

array1 = [
    {id: "1", policy: "abc", date: "20-05-2019" },
    {id: "4", policy: "hjk", date: "12-05-2019" },
    {id: "5", policy: "ikl", date: "08-05-2019" },
    {id: "7", policy: "qwe", date: "20-05-2019" },
    {id: "8", policy: "bdd", date: "04-05-2019" },
]

I have another large array like this:

array2 = [
 {
   "info" : { "insuredPolicy" : "qwe", },
   "date" : { "sDate" : 20-05-2019, "eDate" : 20-06-2019 }
 },
 {
   "info" : { "insuredPolicy" : "ikl", },
   "date" : { "sDate" : 20-05-2019, "eDate" : 20-06-2019 }
 },
{
   "info" : { "insuredPolicy" : "bbb", },
   "date" : { "sDate" : 20-05-2019, "eDate" : 20-06-2019 }
 },
{
   "info" : { "insuredPolicy" : "bdd", },
   "date" : { "sDate" : 04-05-2019, "eDate" : 20-05-2019 }
 },
];

I want to compare all policy field & date field in array1 with array2 (assume array2 is very large). then, create array of objects if policy field (array1) matches with insuredPolicy (array2) & date field in array1 matches with sDate in array2

so output will be:

array3 = [
{ policy: "qwe", date: "20-05-2019" },
{ policy: "bdd", date: "04-05-2019" },
];

In learning phase, any help will be really appreciated.

EDIT

How to compare if array2 contains sDate one day ahead? If so, then reduce sDate by 1 day and then compare. How can we achieve this?

Thanks in advance.

Code Maniac · Accepted Answer · 2020-05-01 11:46:25Z

3

You can use filter and Map

Since you mentioned second array is very large so searching every time through complete array increase time complexity
So map the second array into a key,value pair using Map
Filter values from array1 based on values present in Mapper

const array1 = [{id: "1", policy: "abc", date: "20-05-2019" },{id: "4", policy: "hjk", date: "12-05-2019" },{id: "5", policy: "ikl", date: "08-05-2019" },{id: "7", policy: "qwe", date: "20-05-2019" },{id: "8", policy: "bdd", date: "04-05-2019" },]

const array2 = [{"info" : { "insuredPolicy" : "qwe", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},
{"info" : { "insuredPolicy" : "ikl", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},{"info" : { "insuredPolicy" : "bbb", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},{"info" : { "insuredPolicy" : "bdd", },"date" : { "sDate" : '04-05-2019', "eDate" : '20-05-2019' }},];

const mapper = new Map(array2.map(({
  info,
  date
}) => [info.insuredPolicy, date.sDate]))

const final = array1.filter(({
  policy,
  date
}) => {
  if (mapper.has(policy)) {
    return mapper.get(policy) === date
  }
})

console.log(final)

edited May 1, 2020 at 11:46

answered May 1, 2020 at 11:43

Code Maniac

37.9k5 gold badges44 silver badges65 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Vishnu Over a year ago

A small edit required in question, need to reduce sDate one day & then compare with date. eg: if sDate is 05-05-2019, then reduce one day and compare with date in array1.

Code Maniac Over a year ago

@Vishnu parse date using new Date and manipulate in desired manner, or if you project has lots of date related operation use a standard library like moment or date-fns

Vishnu Over a year ago

can you please update with moment or date-fns? It will be very helpful.

Code Maniac Over a year ago

@Vishnu with all due to respect you must try first atleast once, if you still face you can ask here, you will learn by doing yourself, give it a try once and let me know if you still face a difficulty, happy coding

Vishnu Over a year ago

Yes sure, can you please let me know whey used Map here? I didn't get the point.

|

arizafar · Accepted Answer · 2020-05-01 12:06:38Z

2

you can use Array#filter on array1 with Array#some on array2 to filter out the required elements.

const array1 = [{id: "1", policy: "abc", date: "20-05-2019" },{id: "4", policy: "hjk", date: "12-05-2019" },{id: "5", policy: "ikl", date: "08-05-2019" },{id: "7", policy: "qwe", date: "20-05-2019" },{id: "8", policy: "bdd", date: "04-05-2019" },]

const array2 = [{"info" : { "insuredPolicy" : "qwe", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},
{"info" : { "insuredPolicy" : "ikl", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},{"info" : { "insuredPolicy" : "bbb", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},{"info" : { "insuredPolicy" : "bdd", },"date" : { "sDate" : '04-05-2019', "eDate" : '20-05-2019' }},];


 let out = array1.filter(({policy, date}) => array2.some(e => e.info.insuredPolicy === policy && e.date.sDate === date));
 console.log(out)

EDIT: As per new requirement

you can write a method to get the previous date string as following

const array1 = [{id: "1", policy: "abc", date: "20-05-2019" },{id: "4", policy: "hjk", date: "12-05-2019" },{id: "5", policy: "ikl", date: "08-05-2019" },{id: "7", policy: "qwe", date: "20-05-2019" },{id: "8", policy: "bdd", date: "04-05-2019" },]

const array2 = [{"info" : { "insuredPolicy" : "qwe", },"date" : { "sDate" : '21-05-2019', "eDate" : '20-06-2019' }},
{"info" : { "insuredPolicy" : "ikl", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},{"info" : { "insuredPolicy" : "bbb", },"date" : { "sDate" : '20-05-2019', "eDate" : '20-06-2019' }},{"info" : { "insuredPolicy" : "bdd", },"date" : { "sDate" : '04-05-2019', "eDate" : '20-05-2019' }},];


function yesterday(str) {
  return str.replace(/\d{2}/, (p1) => (p1 - 1).toString().padStart(2, 0))
}

let out = array1.filter(({policy, date}) => array2.some(e => e.info.insuredPolicy === policy && yesterday(e.date.sDate) === date));
 console.log(out)

edited May 1, 2020 at 12:06

answered May 1, 2020 at 11:38

arizafar

3,1321 gold badge11 silver badges19 bronze badges

2 Comments

Vishnu Over a year ago

A small edit required in question, need to reduce sDate one day & then compare with date. eg: if sDate is 05-05-2019, then reduce one day and compare with date in array1.

arizafar Over a year ago

@Vishnu added the solution for that as well.

Nina Scholz · Accepted Answer · 2020-05-01 12:17:14Z

You could take an object as map and increment for the firts array and decrement for the second. At the end take only the keys with value zero and parse the key as JSON for a new object.

var array1 = [{ id: "1", policy: "abc", date: "20-05-2019" }, { id: "4", policy: "hjk", date: "12-05-2019" }, { id: "5", policy: "ikl", date: "08-05-2019" }, { id: "7", policy: "qwe", date: "20-05-2019" }, { id: "8", policy: "bdd", date: "04-05-2019" }],
    array2 = [{ info: { insuredPolicy: "qwe" }, date: { sDate: "20-05-2019", eDate: "20-06-2019" } }, { info: { insuredPolicy: "ikl" }, date: { sDate: "20-05-2019", eDate: "20-06-2019" } }, { info: { insuredPolicy: "bbb" }, date: { sDate: "20-05-2019", eDate: "20-06-2019" } }, { info: { insuredPolicy: "bdd" }, date: { sDate: "04-05-2019", eDate: "20-05-2019" } }],
    wrapper1 = ({ policy, date }) => JSON.stringify({ policy, date }),
    wrapper2 = ({ info: { insuredPolicy: policy }, date: { sDate: date } }) => JSON.stringify({ policy, date }),
    map = Object.create(null),
    setMap = (map, wrapper, value) => object => (key => map[key] = (map[key] || 0) + value)(wrapper(object)),
    result;

array1.forEach(setMap(map, wrapper1, 1));
array2.forEach(setMap(map, wrapper2, -1));

result = Object
    .entries(map)
    .filter(([, v]) => !v)
    .map(([k]) => JSON.parse(k));

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

AlexOwl · Accepted Answer · 2020-05-01 11:43:08Z

0

You can use .reduce() to create new array based on your conditions

var array1 = [
    {id: "1", policy: "abc", date: "20-05-2019" },
    {id: "4", policy: "hjk", date: "12-05-2019" },
    {id: "5", policy: "ikl", date: "08-05-2019" },
    {id: "7", policy: "qwe", date: "20-05-2019" },
    {id: "8", policy: "bdd", date: "04-05-2019" },
]

var array2 = [
 {
   "info" : { "insuredPolicy" : "qwe", },
   "date" : { "sDate" : "20-05-2019", "eDate" : "20-06-2019" }
 },
 {
   "info" : { "insuredPolicy" : "ikl", },
   "date" : { "sDate" : "20-05-2019", "eDate" : "20-06-2019" }
 },
{
   "info" : { "insuredPolicy" : "bbb", },
   "date" : { "sDate" : "20-05-2019", "eDate" : "20-06-2019" }
 },
{
   "info" : { "insuredPolicy" : "bdd", },
   "date" : { "sDate" : "04-05-2019", "eDate" : "20-05-2019" }
 },
];

console.log(array2.reduce((arr, { info: { insuredPolicy }, date: { sDate } }) => {
  var item = array1.find(({ policy, date }) => insuredPolicy == policy && sDate == date)
  if(item) arr.push({ policy: item.policy, date: item.date }) // edit as you want
  return arr
}, []))

answered May 1, 2020 at 11:43

AlexOwl

8775 silver badges11 bronze badges

1 Comment

Vishnu Over a year ago

A small edit required in question, need to reduce sDate one day & then compare with date. eg: if sDate is 05-05-2019, then reduce one day and compare with date in array1.

Collectives™ on Stack Overflow

filter data from an array of objects based on another array of objects

4 Answers 4

6 Comments

2 Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

6 Comments

2 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related